Structural expansion joint



Nov. 12, 1968 A. H. EMPSON ETAL 3,410,031.

STRUCTURAL EXPANSION JOINT Filed' Oct. 20, 1966 F l INVENTOR-S AZARIAH H. EMPSOM ROBERT JPICKELsIMER AT TY.

United States Patent 3,410,037 4 p T STRUCTURAL EXPANSION JOINT Azariah H. Empson, Stow, and Robert J. Pickelsimer, Akron, Ohio, assignors to The B. F. Goodrich Company, New York, N.Y., a corporation of New York Filed Oct. 20, 1966, Ser. No. 588,032

2 Claims. (Cl. 52-58) ABsTnAcr OF THE DISCLOSURE I This disclosure" relates to structural expansion joints and more particularly to a roof or wall joint having an inverted V-shaped bridging member which is covered by an insulation strip and enclosed by'a flexible flashing.

a This invention relates to expansion joints for use in roofing joints and other similar structural joints to compensatel for thermal expansion andcontraction of the structural material.

-The expansion joint seal of this invention is uniquely simple and capable of low cost fabrication and installation, as compared with the presently known structiures for sealing roof expansion joints. Additionally, the seal of this invention provides ,a permanent thermal insulation along the entire length of the expansion gap.

According to the invention, a roof expansion gap is covered and closed by aninverted Y-shapechannel which bridges between the roof members defining the gap and extends lengthwise along the gap. A thick insulation barrier is positioned so that it covers the side of the channel directed away from the gap, and this insulation barrier is in turn covered and enclosed by a flexible flashing which is attached to the opposing edges of the roof members. The bridging channel is preferably a plastic extrusion having an inverted V-shape cross-section and longitudinal grooves at pre-determined flex points to provide substantially unrestrained hinge action in response to variation in the width of the gap between the roof members. The insulation barrier is preferably a flexible sponge material that deforms to compensate for gap width variation so that the overlying flashing strip is not subject to direct shear loads parallel to the roof members.

The invention will be further described with reference to the accompanying drawings which illustrate two separate applications of expansion joints embodying the principles of this invention. The first application being a preferred roof expansion joint for horizontal installations and the second being a preferred wall expansion joint for vertical installations.

FIGURE 1 is a cross-section of the installation of the roof expansion joint bridging the gap between two horizontal roof members.

FIGURE 2 is a cross-section of the basic extruded channel of the roof expansion joint.

FIGURE 3 is a cross-section of the installation of the wall expansion joint bridging the gap between two vertical wall members.

The roof expansion joint of FIGURE 1 which joins adjacent roof members 12 and 14 includes a chanel frame 15 which bridges the gap A between the roof members 12 and 14 along the length of this gap. The frame 15 is covered by an overlying insulation strip 16 to insulate gap A. Both frame 15 and strip 16 are enclosed by a flashing strip 17 which is fastened or cemented along its edges to the roof members 12 and 14.

Referring to FIGURE 2, channel frame 15 is preferably a polypropylene extrusion having two center bridge members 18 and 19 joined in an inverted V shaped cross-section, and two integral lateral attachment margins 22 and 24 at the free ends of bridging members 18 and 19. A

retaining rib 26 is integrally connected along attachment margin 22 and a similar retaining rib 28 is similarly connected to the opposite attachment margin 24. A longitudinal groove 34 at the peak of the inverted V cross-section formed by bridging members 18 and 19 and two similar grooves 36 and 38 at the base of members 18 and 19 permit flexure of the frame 15 about these grooves in response to any change in the width of gap A without substantially bending bridge members 18 and 19. A narrowing of gap A results in a steeper slope for bridge members 18 and 19, and, reversely, a widening of gap A results in a reduced slope for bridge members 18 and 19.

The unassembled channel frame 15 of FIGURE 2 further.

includes two adjustable parallel edges 44 and 45 integrally bordering margin 22 and retaining rib 26. These edges 44 and 45 each have two longitudinal grooves 48, 48 which allow either edge to be folded towards the other to provide a gradually sloping edge for channel frame 15 when assembled.

Similarly, the opposite margin 24 and retaining rib 28 includes two integral parallel edges 46 and 47 with longitudinal grooves 50, 50 as shown in FIGURE 2.

Referring to FIGURE 1, the flexible, preferably sponge, insulation strip 16 is loosely laid over the inverted V- shaped portion of channel 15 formed by bridge members 18 and 19 so that the lengthwise edges of strip 52 are nested in the retaining ribs 26 and 28 at the margins of frame 15.

A flexible, preferably vinyl weather flashing 17 encloses both the channel frame 15 and insulation strip 16. The center portion of flashing 17 directly covers insulation strip 16 and the opposite marginal edges of flashing 17 are cemented or otherwise fastened to the exposed faces of roofing members 12 and 14 as shown in FIGURE 1. In the preferred form of fabrication, flashing 17 is not bonded to insulation strip 16 in order to permit unrestricted movement of the strip 16 and the bridging members 18 and 19 of frame 15 underneath flashing 17.

When the thermal expansion or contraction of roof members 12 and 14 move them closer to each other or further apart as the case may be, the bridging members 18 and 19 accordingly pivot at grooves 34 and 36, 36, so that the slope of these bridging members will increase on expansion and decrease on contraction.

The flexible and compressible properties of insulation strip 40 enable this strip to take up slack or deform to any respective relaxing of tension or increasing of tension on flashing strip 17. This feature coupled with the bridging frame construction of this improved expansion joint virtually eliminates the shear stresses which ordinarily act on conventional flashing strips as a result of the parallel movement of the joined structures in response to temperature change.

In the horizontal installation of the expansion joint 10 of FIGURE 1, channel frame 15 is attached to the exposed edges of roof members 12 and 14 by fastening or preferably cementing the undersides of margins 22 and 24 to roof members 12 and 14. The underside of the lower border edge 44 is also fastened or cemented to roof member 12 and the adjacent upper border edge 45 is folded at grooves 48 and cemented to lower edge 44 to give channel frame 15 a gradually sloping edge as shown in FIGURE 1. Similarly, the opposite lower border edge 46 is cemented to roof member 14 and the upper border edge 47 is folded downward and cemented to the horizontal lower edge 46.

After channel frame 15 is attached to roof members 12 and 14, the insulation strip 16 is laid over frame 15 with one lengthwise edge tucked into retaining rib 26 and the other edge tucked into retaining rib 28 on the opposite side of frame 15.

Finally, the flashing strip 17 is laid over both frame 15 and insulation strip 16 and one margin of flashing 17 is cemented to roof member 12 and border edge 45 and the other margin of flashing 17 is cemented to roof member 14 and border edge 47 as shown in FIGURE 2.

FIGURE 3 illustrates the preferred manner of applying expansion joint 60 embodying the principles of the invention between two vertically spaced wall sections 62 and 64 or in any other application where the expansion joint must be internally installed. In this vertical installation, the expansion joint 60 includes the same structural elements used in the horizontal expansion joint previously disclosed.

However, in installing this vertical expansion joint 60, it is preferable to completely assemble the expansion joint before applying it to the inside faces of the two vertical wall sections 62 and 64. The insulation strip 16 is nested into the restraining ribs of frame 15 and the flashing strip:

17 is placed over insulation strip 16 and cemented at its opposite margins to the edges of frame 15. In this assembled joint 60, the lower border edges 44 and 46 are folded along grooves 48 and 50 and bonded to their respective border edges 45 and 47.

This assembled expansion joint 60 is then applied to the inside faces of wall sections 62 and 64 so that the flashing strip 17 is directed outwardly between gap B towards the exposed sides of wall sections 62 and 64 and the marginal edges of expansion joint 60 are cemented to the inner faces of wall sections 62 and 64.

We claim:

1. An expansion joint comprising a plastic channel frame member including two opposingly inclined rectangular bridging sections joined along a common longitudinal edge, each of said bridging sections having outwardly extending base margins integrally joined to the remaining longitudinal edges of said bridging sections, a

longitudinal groove at the junction of said bridging sections and at the junction of each of said bridging sections with its respective base margin thereby providing three hinge points to permit substantial change of the relative inclination of the bridgingsections to each other without deflection of said sections, a foam insulation strip overlying said channel frariie member, meanson said integral base marginsfor restraining the opposing lengthwise edges of said foam insulation strip, and a flexible weatherproof flashing covering and enclosing said-insulation strip and said channel frame.

2. An expansion joint according to claim 1, wherein said insulation restraining means includesa restraining rib extending longitudinally along each of "said base margins in opposing relationship to limit the maximum Width of said insulator strip.

References Cited UNITED STATES. PATENTS Re. 25,733 2/1965 Patty etal. 5 2396 3,375,621 4/1968 Curtiset al. 52 -58 1,357,713 11/1920 Lane 5 2 -46'8 X 2,730,969 1/1956 Perry 5 2-276 3,093,934 6/1963 Underhill 52277 3,200,547 8/1965 Johnson 52 71 6 X I 3,300,913 1/1967 Patry et al. 52-58 X FOREIGN PATENTS 820,727 9/1959 Great Britain 348,539 10/1960 Switzerland.

FRANK L. ABBOTT, Primary Examiner.

CHAS. G. MUELLER, Assistant Examiner. 

